The present invention relates to nonwoven fabrics and particularly to nonwoven fabric containing thermoplastic elastomer fiber used for sanitary article.
Nonwoven fabric containing polyurethane-based thermoplastic elastomer (referred to hereinafter as TPU) is conventionally used for clothing or sanitary articles on account of high elasticity and minor permanent elongation. For example, Japanese Unexamined Patent Application Publication No. 2004-131918 discloses elastically stretchable nonwoven fabric formed from elastically stretchable first fiber made of thermoplastic polyurethane and inelastically stretchable second fiber made of polyolefin-based polymer wherein this nonwoven fabric is used for sanitary articles such as disposable diapers, disposable pants and disposable gowns for hospital-use.
As is generally known, synthetic resin is discolored due to UV degradation and, particularly, TPU turns yellow due to conjugate double bond when it is exposed to UV radiation. Specifically, if the sanitary articles are exposed to the sunlight, for example, if the sanitary articles are left exposed to the sunlight on the store shelves, these articles sometimes turn yellow. Particularly in the case of the sanitary articles, such yellow discoloration may seriously reduce commercial value of the articles and/or may cause the articles to be misunderstood as if they are poor in quality.